Anti-Coccidiosis Potential of Autoclaveable Antimicrobial Peptides from Xenorhabdus budapestensis Resistant to Proteolytic (Pepsin, Trypsin) Digestion Based on In vitro Studies

Abstract

Aims: To elucidate the anticoccidial potential of antimicrobial peptides from Xenorhabdus budapestensison both causative pathogens (prokaryotic Clostridium perfringens and eukaryotic Eimeria tenella). Objectives: (1) To establish if the antimicrobial compounds of the cell-free culture media (CFCM) of the entomopathogenic symbiotic bacterium species, X. budapestensis DSM 16342 (EMA) and X. szentirmaii DSM 16338 (EMC) were active against 13 independent pathogenic isolates of Clostridium perfringens in vitro; (2) To create a sterile, autoclaved, bio-preparation called “XENOFOOD”, for future in vivo feeding studies, aimed at determining the efficacy, and side-effects, of EMA and EMC on C. perfringens in chickens. Study Design: Clostridium perfringens samples (LH-1-LH24) were collected from chickens and turkeys, and were deposited in the frozen stock collection of Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science, Szent István University, Budapest, Hungary, where the in vitro assays were carried out on 13 of these isolates. Place and Duration of Study: Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science, Szent István University, Budapest, Hungary between September 2013 and February 2014. Methodology: Adaptation of our previously published in vitro bioassays for aerobic tests for the anaerobic bacteria Clostridium perfringens. When preparing “XENOFOOD” we benefitted from our experimental data about the heat tolerance and endurance to proteolytic enzymatic digestion of the studied antimicrobial peptides. Results: The studied antimicrobial peptides were heat-stable, trypsin and pepsin resistant. All but one of 13 C. perfringens isolates was sensitive to EMA-CFCM. XENOFOOD (made here) is not toxic for chicken, (unpublished). Conclusion: Since these cell-free cultures killed E. tenella cells, but were toxic to permanent chicken liver (LMH) cells, we need to run in vivo feeding tests to determine the gastrointestinal (ileac), anti-Clostridiumand anti-Eimeria biological effects of the these heat, - and proteolysis tolerant antimicrobial peptides.